Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most frequently prescribed drugs for the treatment of pain associated with osteoarthritis and many other musculoskeletal and inflammatory disorders. In the United States, about 100 million prescriptions are written each year to provide effective relief of pain and treatment of inflammatory diseases. Commonly used NSAIDs include sulindac, naproxen, indomethacin, mefenamic acid, diclofenac, fenoprofen, and diflunisal.
However, considerable evidence indicates that NSAIDs have frequent, serious, and costly gastrointestinal tract toxic side effects. These include mild dyspepsia, gastritis, peptic ulcer disease, as well as more serious gastrointestinal complications such as bleeding and perforation, leading sometimes to significant morbidity and, to a lesser extent, mortality. Serious GI complications due to NSAID use represent the greatest threat to life in patients with connective tissue diseases, second only to the primary disease and its complications. Similar gastrointestinal damage is caused by ingestion of alcohol. Indeed, a condition known as ethanol withdrawal syndrome is commonly encountered when prolonged ethanol consumption is terminated. In addition to gastrointestinal damage, this syndrome often results in tremors, anxiety, convulsions, hallucinations, and confusion.
Other commonly encountered gastrointestinal disorders include inflammatory bowel disorders (IBD) and functional bowel disorders (FBD), including dyspepsia. These GI disorders include a wide range of disease states that are currently only moderately controlled, including Crohn's disease, ileitis, ischemic bowel disease, and ulcerative colitis, as well as IBD, the irritable bowel syndrome, dyspepsia, and gastro-esophageal reflux for FBD, and other forms of visceral pain.
Gamma-aminobutyric acid has been shown to activate gastric afferent nerves which, in turn, have been shown to participate in gastric defense mechanisms. We have now discovered that GABA analogs dramatically reduce the gastrointestinal damage caused by drugs and alcohol. The GABA analogs also treat the conditions resulting from ethanol withdrawal syndrome, and GI disorders characterized as IBD and IBS.
All that is required to prevent gastrointestinal damage and to treat IBD, IBS, and alcoholism according to this invention is to administer to a subject who is in need of treatment an effective amount of a GABA analog.
Several GABA analogs are known. Gabapentin, a cyclic GABA analog, is now commercially available and extensively used clinically for treatment of epilepsy and neuropathic pain. Such compounds are described in U.S. Pat. No. 4,024,175. Another series of GABA analogs which are anti-seizure agents is described in U.S. Pat. No. 5,563,175.